[Involvement of serotonergic system in the pathogenesis of non-motor symptoms of Parkinson's disease].

Platelet serotonin content was investigated in 51 patients with Parkinson's disease and compared to the form and severity of non-motor symptoms - depression, anxiety and cognitive dysfunction. An average level of platelet serotonin was 166,8+/-111,1 ng/ml in parkinsonian patients that was significantly lower (p=0,027) compared to the control group (562,7+/-111,1 ng/ml). The platelet serotonin level in the peripheral blood was inversely correlated with clinical form of disease, cognitive deficits and the level of anxiety and depression.